hardness testerclassification

hardDegree test is the simplest and most feasible testing method in mechanical performance testing. In order to replace certain mechanical performance tests with hardness tests, a more accurate conversion relationship between hardness and strength is required in production.

1.Dietmar Leeb（Dietmar Leeb）

Leeb hardness is designed using microprocessor technology based on the Leeb hardness testing principle

2.Brinell hardness（HB）

Under a certain load (usually3000kg）Take a certain size (usually with a diameter of)10mm）The Brinell hardness value is the ratio of the load to the indentation area after the quenched steel ball is pressed into the surface of the material and held for a period of time（HB）The unit is kilogram force/mm2 （N/mm2）.

3.Rockwell hardness（HR）

whenHB>450If the sample is too small, Brinell hardness test cannot be used and Rockwell hardness measurement should be used instead. It uses a vertex angle120°The diamond cone or diameter is1.59The3.18mmA steel ball is pressed into the surface of the tested material under a certain load, resulting in an indentation

Calculate the hardness of the material based on its depth. According to the different hardness of the test materials, there are three different types of loess treesHRA: It is adopted60kgThe hardness obtained from the load and diamond cone indenter is used for materials with hardness * (such as hard alloys, etc.).

HRB: It is adopted100kgLoad and diameter1.58mmThe hardness obtained from quenched steel balls is used for materials with lower hardness, such as annealed steel, cast iron, etc.

HRC: It is adopted150kgThe hardness obtained from the load and diamond cone indenter is used for materials with high hardness, such as quenched steel.

4. Vickers hardness（HV）

with120kgThe load and vertex angle within are136°The diamond square cone indenter is pressed into the surface of the material, and the Vickers hardness value is obtained by dividing the load value by the surface area of the material indentation pit（HV）.

5． Knoop hardness（HK）

Suitable for hardness testing of high hardness materials (generally)HV1000Hardness measurement above hardness.

6.andShore hardness tester

7.Vickers hardness tester（HW）

Suitable for measuring the Vickers hardness value of aluminum alloy products.

8.Gypsum hardness tester

Suitable for measuring the hardness of building gypsum, place a steel ball on a specimen, measure the depth of the ball mark under a fixed load, and calculate the gypsum hardness of the specimen.

The above hardness is just a few commonly used, in addition to Shore hardness（HS）hardnessShaw Brothers（HS）hardnessBa Baharddegree、 摩氏hardnessWait. Practice has proven that there is an approximate correlation between the various hardness values of metal materials, as well as between hardness values and strength values. Because the hardness value is determined by the initial plastic deformation resistance and the continued plastic deformation resistance, the higher the strength of the material, the higher the plastic deformation resistance, and the higher the hardness value.